| 摘要 |
PURPOSE: To obviate the degradation in appearance quality occurring in the visual recognition of the adhesive state of adhesives from outside in transparent inner peripheral side parts where a reflection film is not formed. CONSTITUTION: The inner peripheral side parts 6 existing on the side inner in a diametral direction than the signal recording regions of a disk-shaped thin type substrate 2 which forms a disk substrate by superposing and adhering separately formed two sheets on and to each other are roughened on at least one surface. |
